Re: [PATCH 01/13] arm64: mm: Add p?d_large() definitions

From: Peter Zijlstra
Date: Mon Feb 18 2019 - 06:29:37 EST


On Fri, Feb 15, 2019 at 05:02:22PM +0000, Steven Price wrote:

> diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
> index de70c1eabf33..09d308921625 100644
> --- a/arch/arm64/include/asm/pgtable.h
> +++ b/arch/arm64/include/asm/pgtable.h
> @@ -428,6 +428,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
> PMD_TYPE_TABLE)
> #define pmd_sect(pmd) ((pmd_val(pmd) & PMD_TYPE_MASK) == \
> PMD_TYPE_SECT)
> +#define pmd_large(x) pmd_sect(x)
>
> #if defined(CONFIG_ARM64_64K_PAGES) || CONFIG_PGTABLE_LEVELS < 3
> #define pud_sect(pud) (0)
> @@ -435,6 +436,7 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
> #else
> #define pud_sect(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
> PUD_TYPE_SECT)
> +#define pud_large(x) pud_sect(x)
> #define pud_table(pud) ((pud_val(pud) & PUD_TYPE_MASK) == \
> PUD_TYPE_TABLE)
> #endif

So on x86 p*d_large() also matches p*d_huge() and thp, But it is not
clear to me this p*d_sect() thing does so, given your definitions.

See here why I care:

http://lkml.kernel.org/r/20190201124741.GE31552@xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx